by In a breakthrough discovery, researchers from the University of Michigan have identified the protein that enables mammals to sense cold, shedding light on a previously unknown aspect of sensory biology. The study, published in Nature Neuroscience, marks a significant milestone in understanding how humans perceive and react to cold temperatures, particularly in the context of certain disease conditions.
The quest to uncover these temperature sensors began over two decades ago with the identification of a heat-sensing protein known as TRPV1. Despite numerous studies revealing proteins responsible for detecting hot and warm temperatures, the mechanism behind sensing cold temperatures below 60 degrees Fahrenheit remained elusive.
Building on earlier research that identified a cold-sensing receptor protein in Caenorhabditis elegans, a tiny worm species used as a model for sensory studies, scientists were able to pinpoint a similar protein in mammals. This protein, named GluK2 (short for Glutamate ionotropic receptor kainate type subunit 2), was found to play a crucial role in sensing cold temperatures.
The team of researchers conducted experiments on mice lacking the GluK2 gene, which prevented them from producing the GluK2 protein. The results showed that these mice exhibited normal responses to hot, warm, and cool temperatures but were unresponsive to extreme cold stimuli, indicating the essential role of GluK2 in cold sensation.
Notably, while GluK2 is primarily located in the brain where it facilitates neuron communication, it is also expressed in sensory neurons in the peripheral nervous system. This dual function suggests that GluK2 processes temperature cues in addition to chemical signals, underscoring its significance in cold perception.
Professor Shawn Xu, a lead researcher in the study, speculates that temperature sensing may have been an ancient function of GluK2, dating back to single-cell organisms. This evolutionary perspective sheds light on the protein’s role in environmental sensing and its eventual adaptation in more complex nervous systems.
Beyond advancing our understanding of temperature perception, the discovery of GluK2 as a cold sensor has potential implications for human health. For instance, cancer patients undergoing chemotherapy often experience heightened sensitivity to cold temperatures, which could be linked to GluK2 malfunction.
Professor Xu envisions that the identification of GluK2 as a cold sensor in mammals could pave the way for targeted therapies to mitigate cold-induced pain in patients with oversensitive cold sensation. This finding not only deepens our knowledge of sensory mechanisms but also offers promising avenues for addressing cold-related discomfort in clinical settings.
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1. Source: Coherent Market Insights, Public sources, Desk research
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